UtahJohn

New here, new used car for wife. Never had a GL before (have a 2006 Sprinter). Have a lot of mechanical aptitude, but can't find a quick guide on changing the filters on this thing.

I already did the cabin filters, easy.

Oil filter is easy.

Fuel filter, I see it, but not sure how tough yet, looks pretty straightforward. Same filter as the Sprinter, I already had one! :-D

However on the air filters I could use a couple sentences of guidance, or a link for a how-to.

Much appreciated in advance!

alx

The air filter replacement on the diesel requires engine adaptations to be reset via das. Failure to do so will mess up the calculation of next service type.

UtahJohn

I just went ahead and did it. Here it is for the next guy.

Remove cross brace (it's in the way of the filter housing R&R)
Unplug electrical connectors to all intake air ducts
Loosen three clamps and remove center air ducts going to turbo and filter housings
Remove fresh air hoses from lower front of filter housings
The L&R filter canisters have 4 torx bolts (2 on each) holding it down to the cylinder head, one front and one rear. The front one is easy to see and very accessible, the real one is hidden. REMOVE the front ones, the rear ones are loosened but stay attached to the filter housing once out of the head.
Wiggle and pull the filter housing straight up, to remove the locating posts from the rubber grommets.
Remove the 4 torx screws on each canister and replace filters.

Installation is the reverse of removal. Getting the filter housing posts into the locating grommets was the most difficult part of the job. I figured out after too much fighting that if I shined a flashlight between the head and filter housing, tilting the housings outward at the top, I could see the posts and guide them into the grommets. Get the posts started, then push the top of the housings inward and get that rear torx bolt started. It's a job done by feel, you can't see it at all. If you get frustrated take a break (I did on the left one). Then start the front one, and tighten both, then do the other side.

When re-installing the T piece to the turbo, do the right side first, then start the center on the turbo, then do the left side. Getting all the boots onto the filter housings and turbo inlet are delicate, it's very easy to get a boot folded over if you rush. Go slow. Each filter housing boot has 2 ears you can pull on to wiggle the boot onto the filter housing, they work well. Once all 3 are on, tighten the clamps.

I did the fuel filter too. The air filters, fuel filter, and cabin filter took me 2 hours, it was the first time I had done this job or even worked on a MB. Next time I'll have it done in 90 minutes, not rushing.

My air filters were very dirty, full of flies and bees that had gotten sucked into the inlets. Cabin filters were just as dirty. Both had been replaced 20k miles ago according to logs.

N_Jay

I am still trying to figure out EXACTLY what happens if you don't do the adaption.


Seems it would "learn" the new flow rates, especially if the "old" filter was not too bad.


Anyone REALLY know?

UtahJohn

Our CEL went on for 50mi and 3-4 starts after my filter changes. Then it went back out. I expected this, no big deal. I even warned the wife that it may occur, so she didn't freak out if/when it did.

alx

Resetting adaptations establishes the new flow air flow rate as the "new filter" rate at any throttle level. Certain reduction of that flow rate over time is what triggers a service requiring the air filter change. Failure to reset the adaptations will break this mechanism and air filter change requests will be based strictly on mileage as opposed to actual filter element reduction of air flow.

There is no "learning" per se. The "new filter" flow rate is estsblished some short time after the adaptations are reset. What I do not know is if it is a hard coded value (oem air filter) or is based on the actual flow rate after the reset.

N_Jay

So it sounds like the engine management operates on actual airflow, and therefore filter restriction is constantly compensated for.
Filter replacement is measured by some reduction of flow above a baseline set when you run the adaption of a new filter, so not resetting it may cause an early trigger if the new filter is more restrictive or a later trigger if the filter is less restrictive.
If you are replacing the filter by time before the notice is tripped, this should not matter.


However, if the replace filter also has a time or miles component, THEN you may get a "Replace Filter" indication falsely since the system will not know the miles/time of the last replacement.


Are we sure the system has this time/miles trigger?

Summit Benz

So nJ or ax. Do either of you know how the adaption is performed with the das. I have a autoingunity set up and have a option to reset a few air filter adaptions but to my knowledge nothing has happened yet?? I can let you know what the operations say exactly later.

N_Jay

I don't know and that is why I am asking.


My assumptions are based on what I have been told, but I am still trying to confirm.


(Hence the questions in my posts)